On Thursday, 2 July 2020 13:41:41 UTC+1, Thomas Prufer wrote:
Given: plywood, jigsaw
wanted: circular bit of plywood, diameters 60-80 cm, small hole in the middle is
OK.

Yeah: "make a jig", i.e. an arm with the wanted radius, attached to the jigsaw
base, screw middle down and cut around.

But: I seem to recall there's a catch there somewhere, or a best way of doing
this, in positioning the radius arm with respect to the blade. Should the radius
arm attach to the jigsaw a) ahead of the blade, b) exactly off to the side of
the blade, or c) further back from the jigsaw blade?


Thomas Prufer

How about this approach? A jigsaw table with a blade stabiliser mechanism. Could be worth it if you are going to do this repeatedly.

https://youtu.be/wFnbcOLF4qU

JSK-koubou
565K subscribers
Hey guys, I made a jigsaw table this time.

[Download the plan here]
https://jisaku-koubou.com/downloads/j...
【Plan List】
https://jsk-koubou.stores.jp/

2-way locking arm system allows you to control your jigsaw easier than ever..
Even with a large project, the arm will not get in your way. The arm accepts longer blades up to 150mm, you can cut any lumbers as thick as 100mm without any issues.

The table is also equipped with a T slot for circular cutsΦ80~Φ450ｍｍ) and a foot pedal for maximum efficiency and control.